Integrated circuits are formed from a substrate or semiconductor substrate over which are formed patterned microelectronics layers. In the processing of the substrate, plasma is often employed to deposit films on the substrate or to etch intended portions of the films. Shrinking feature sizes and implementation of new materials in next generation microelectronics layers have put new requirements on plasma processing equipment. During plasma processing, hundreds of substrates may be processed. However, not all processed substrates are of acceptable quality standard. The smaller features, larger substrate sizes, and new processing techniques require improvement in plasma processing apparatuses to control the conditions of the plasma processing, and among other things, this calls for plasma processing apparatuses with improved uniformity, consistency, and self-diagnostics. Therefore, to identify the substrates that may not be of acceptable quality standard, fault detection may be implemented. As discussed herein, fault detection refers to the process of identifying potential problematic substrates.